Answer:
(a) 
(b) 
(c) 
Step-by-step explanation:
We have given velocity as function of t 
Acceleration is equation rate if change of velocity with respect to time
So 
(a) Acceleration at t = 5 sec

(b) Acceleration at t = 10 sec

(c) Acceleration at t = 20 sec

Answer:
Pythagoras theorem.
hypotenuse²=height²+base²
x²=15²+12²
x²=225+144
x²=329
x=329½
x=19.20
Time=distance/speed
621÷51.75
=12
So it takes 12 hours
Answer:
$134.18
Step-by-step explanation:
6.5% = 0.065
$125.99 × 0.065 = $8.19
$125.99 + $8.19 = $134.18